When imaging the human eye in vivo, the patient is typically asked to fixate on a fixation target of a viewing surface. For relatively narrow field of view imaging, the patient is asked to fixate on a number of successive targets in rows and columns on the fixation graphic. The process of fixating on one or more fixation targets can be mentally and physically exhausting. Despite the patient's best efforts, the patient's eyes move in both translation and rotation during the imaging process.
Patients with eye disease are more likely to need imaging of damaged structures of their eyes. Unfortunately, it can be more difficult such patients with disease damaged eyes to fixate on a target. Also, because of severe damage to parts of the eye, it may not be possible to fixate on some of the fixation targets.